1. Field of the Invention
The present invention relates to a program plate for a timer with setting means preferably arranged about the circumference of the program plate for the determination of a switching program, wherein the program plate is rotatably connected with a clockwork drive mechanism for operation of the program plate, and an additional time display which is operable through a further drive mechanism, which evidences a higher timewise resolution than the program plate, and which is integrated into the program plate.
2. Discussion of the Prior Art
Program plates of the type described hereinabove are basically known in the state of the art. Thus, from the disclosure of German Published Patent Application No. 16 15 034 there can be ascertained a timer with a rotatable program plate into which there is integrated an additional time display in the form of a common numerical clock dial with hour and minute hands. The program plate incorporates undetachable slide contacts along its circumference, which are displaceable between two latching positions, and which are sensed by means of a cam with respect to their latching position (switching program). Thereby, one complete rotation of the program plate corresponds to a time interval of 24 hours, whereas the width of a slide contact corresponds to a time interval of 30 minutes (48 slide contacts). The program plate, as well as the hour and the minute hands are operated by means of three central, coaxially arranged axles by a clockwork mechanism, wherein an additional drive, or additional drive components (hereinbelow designated as a further drive) is necessary for the hour and minute hands inasmuch as the program plate effects only one rotation within 24 hours. Hereby, the program plate and the hands are mechanically coupled so that, for a set clock, there can be precisely maintained the switching points of the program plate.
However, any setting of that type of timer is then almost impossible through rotation of the switching plate since the additional drive mechanism with the coupled hour and minute coupled thereto must always be moved therewith. In a timer constructed pursuant to German Published Patent Application No. 16 15 034, there is accordingly provided a turnknob which is coupled with the minute hand, by means of which the time can be set. However, especially for timers which must be set frequently, for instance, socket plug timers, this is extremely cumbersome and time-consuming. Furthermore, the relatively complicated construction of the clockwork mechanism for the operation of three displays hands which rotate at different speeds necessitate a large constructional volume, while the construction, in general, is complicated and thereby more susceptible to breakdowns and is more expensive.
Furthermore, also known in the art are a large number of different kind of program plate constructions whose rotational speed for one rotation is constituted of either 24 hours or 7 days, and which do not incorporate any additional time display with a higher timewise resolution. Program plates of that type are, as a rule, directly rotatable by hand in a simple manner and also necessitate only a small-sized drive mechanism with a single drive output speed. Any precise setting to the currently actual time is, however, extremely difficult, in particular for weekly program plates, and partly completely impossible.